Deformable switch



Patented Mar. 16, 194% UNITED sTATes .entrar ori-lcs DEFORMABLE SWITCH Nathan Paul, Long Island, N. Y., assigner to Elliott F. Barlow, Yonkers, N. Y.

Application January 24, 1946, Serial No. 643,059

(Cl. 20G-86) 7 Claims. 1

My lnventionrelates to deformable switches, and more particularly to a switch operable by being compressed at any point along its length.

Such switches are useful as emergency controls for machinery, safety controls for opening and closing doors; controls for pneumatic equipment; signal controls, remote control at any point along the line in place of many individual single unit types; controls for aircraft runways; counters for automobiles, and for many other similar uses.

Among the objects of my invention are to provide a switch oi the foregoing character which can be quickly placed on the ground, water, or in the air, and which is immediately responsive when compressed at any longitudinal point and in any transverse direction thereon, to close the electrical circuit contained therein; which can be stepped on, rolled up and coiled without damage or circuit closure; which may be made continuously and inexpensively; which is sensitive to pressures without being fragile or easily damaged; which may contain a reinforcing cable and which may contain a pilot circuit for checking purposes.

l accomplish these and other objects and obtain my new results as will be apparent from the device described in the following specification, particularly pointed out in the claims, and illustrated in the accompanying drawing in which:

Fig, l illustrates a longitudinal View, partly in section, of a length of switch employing my invention;

Fig. 2 is a longitudinal sectional View of a modification thereof;

Fig. 3 is a cross-sectional view taken in the plane 3-3 of Fig. 2;

Fig. 4 illustrates a longitudinal sectional view of still another modification;

riff. 5 is a cross-sectional view of a mcdied central electrode;

Fig. 6 is a cross-sectional view of a further modification;

Fig. 7 is a cross-sectional view of a modified form of insulating spacer which may be employed in my invention.

Referring more in detail to my invention, reierence numeral It designates a section of hollow rubber tubing containing within it a length of tubular metal braid ll. Centrally positioned inside the braid, a central coil of wire l2 is located, supported by aperture insulating separators i3, preferably made of rubber.

The rubber separators or spacers are designed with suitable resiliency and thickness and spaced apart sufiiciently to produce the desired sensitivity of operation, taking into consideration the braid and outer wall of the tube, when coi..- pressed.

The spacers may be tightly drawn over the coi d wire, thus maintaining themselves when positioned; or glued or otherwise secured thereto to prevent movement with respect to the wire.

The wire is of springy metal suitable for carrying current, such as phosphor bronze. The flexible tubular braid is made of finer wire than the coil spring, but sufficiently flexible to withstand deformation.

I prefer to make the separators or spacers oi lesser diameter than the braid, to enable the spacers and coiled spring to be easily pulled through the hollow braid.

The braided tube l i may be bonded to the rubber cover by adhesives, or by being molded thereto, making sure that the inner surface of the braided tube is uncovered and free from rubber or adhesive, which Inigit prevent contact between the braid and coiled spring.

The proportions of the various parts for all sizes are approximately as shown in Fig. 1 of the drawing; as such the rubber tube, braided metal tube, spacers and coiled spring are suciently strong and resilient to withstand damage when an automobile is rolled over a tube approximately three-quarters of an inch in outside diameter.

The metal braided tube may be made of the same type of coiled spring as is the centrally supported section, but greater sensitivity is obtained with the combination illustrated in Fig. l..

The ends of the outer tube may be provided with male and female plug and socket devices it and i5, respectively, for connecting a plura of lengths, in addition, by providing gas tio Lt connections, the tubular lengths may be filled with oil for arcing control.

in Fig, 2 special separators are provided with peripheral angular substantially xl-shaped grooves into which conductors iii are positioned, which are connected to the central coiled spring i9, by suitable means, such as the extending conductor ends 2i) which engage the coiled spring through the radially formed bore 2|, as shown in Figs. 2 and 3.

The action of the separator to accommodate the compressed outer tube 22, is shown by spacer Ila whose peripheral gro-ove has been flattened to permit the braided outer conductor 23 to contact the conductor 18a in the groove, thus closing the circuit.

In Fig. 4, a further modification of Ymy device is shown, employing the outer tubular resilient cover 3), the braided metal tube 3i, and a resilient center section 32, which is preferably made of rubber and provided with a spiral groove 33, into which a conductor 34 is positioned. The grooves are similar to those shown on the separater it in Fig. 2, and have a re-entrant angle of approximately 60 with the conductor spaced about Tre" from the outer portion of the section which will function to contact the braid when the braided metal tube 3| fiattens the spiral edges 35 and :it similarly to that shown in Fig. 2.

The spirally shaped groove 33 may be molded in the section 32.

VIt is possible to actually weave the braided tube over the resilient insulating center section and coil spring to produce a continuous length of concentric conductors separated by the resilient center section, over which the rubber cover may be continuously formed.

In Fig. 5,the inner coiled wire electrode itil, such as is used in Figs. 2 and 3, is provided with a stranded cable Qi which extends throughout the length of the switch.

Thus, where the switch is strung between two fixed points of considerable length, the weight of the switch may be carried by means of the cable il without stressing any of the remaining parts, such as the cover c2, the braided tube t3 or the coiled wire 40.

A further modification of the central portion ci the switch is shown in section, Fig. 6, 'wherein the coiled wire 5S contains -a third electrode 5i separated by insulator 52. The third electrode may be selectively connected to either of the other two electrodes 50, or the braided metal tube '53, through a `pilot light or relay, acts as a detector of any fault in the switch. Preferably, the live line of the two electrodes should be so connected to the pilot, The third electrode '5l may be of suiiioient strength to act as an insulated cable support for the entire length of the switch.

In Fig'. 7 I have disclosed an insulation spacer 60 provided with an outwardly tapered peripheral edge B i, to facilitate compression, and an inwardly tapered edge t2 which seats itself in the grooves between the coils, thus assisting in the prevention of longitudinal movement.

The thickness and composition of the outer covering; the guage and spacing of the braided or meshed outer electrode; the thickness, diameter, composition and spacing of the spaces or insulating section between the outer and inner electrodes; the re-entrant angle of the insulating section and the distance between the two electrodes, all can be varied to obtain the desired degree of sensitivity of the switch.

The outer covering may be made of suitable material such as synthetic plastics, treated textiles or other materials, that are unaifected by solvents such as water, oil or gases. It will be noted that I do not rely on the outer covering to restore the shape of the switch after deformation. The outer braided electrode may be made of springy metal, having sufcient resiliency and temper to restore itself to its original shape, or the spacers or insulating sections which can be made of various suitable materials may be utilized for this purpose.

In the foregoing devices, I have described a deformable switch, operable at any point circumferentially along its length to cause a circuit to close. Such circuit may directly operate a device such as an alarm, etc., or cause the device to stop operating, through a relay, in a manner familiar to anyone skilled in the art.

The construction permits the manufacture-of switches of any length, unitary or divisible into separable units, which may be made waterproof, at the connections, or inside the switch itself, to function as explosion proof switching mechanism in mines or other localities where explosive gases may be ignited by a connecting or disconnecting circuit, as a submarine cable, where an elongated switch may be subject to great stresses necessitating reinforcement, and for other uses too numerous to mention.

I have thus described my invention, but I desire it understood that it is not confined to the particular forms or uses shown and described, the same being merely illustrative, and that the invention may be carried out in other ways without departing from the spirit of my invention, and, therefore, I claim broadly the right to employ all equivalent instrumentalities coming within the scope of the appended claims, and by means of which, objects of my invention are attained and new results accomplished, as it is obvious that the particular embodiments herein shown and described are only some of the many that can be employed to attain these objects and accomplish these results.

I claim:

1. A switch comprising a compressible insulating cover; a tubular flexible electrode made of braided springyl metal contained within the cover; a second electrode contained within the tubular electrode; and insulating spacer means positioned between and normally separating the two electrodes; said tubular electrode being compressible to establish contact with the second electrode when said insulating cover compresed, and being restorable by the combined action oi said insulating spacer and the natural resiliency of said iiexible electrode to its original position when the pressure is released.

2. The switch or" claim l wherein the spacer means is provided with a peripheral, substantially V-shaped groove seating a conductor and the conductor is connected to the second electrode.

3. The switch of claim l provided with a centrally positioned insulating support upon which the second electrode is spi-rally wound.

4. The switch of claim 3 wherein the spacer means extends from the centrally positioned insulating support.

5. The switch of claim 3 wherein the spacer means is integral with the centraiiy positioned insulating support, and spirally shaped.

6. A switch comprising a compressible insulating cover; a ilexible tubularly shaped electrode made of springy metal contained within the cover; a spirally shaped second electrode contained within the tubular electrode; a centrally positioned insulating support upon which the second electrode is spirally shaped, and insulating spacer means positioned between and normally separating the two electrodes, said tubular electrode being compressible to establish contact with the second electrode when said insulating cover is compressed and being restorable to its original position by the combined action of said insulating spacer and the natural resiliency of said iiexible electrode when the pressure is released.

7. The switch of claim 1, wherein a, plurality of inner electrodes are provided, all positioned within the tubular ilexible electrode, said inner electrodes being separated from each other by insulation.

NATHAN PAUL.

REFERENCES CITED The following references are of record in the le of this patent:

10 Number UNITED STATES PATENTS Name Date Cox Apr. 20, 1386 Broekman Sept. 30, 1930 Bassett Nov. 1, 1938 FOREIGN PATENTS Country Date Great Britain June 17, 1927 Great Britain June 18, 1927 Great Britain Aug. 30, 1923 

